// 函数组合
function compose(f, g) {
    return function(value) {
        return f(g(value));
    }
}

 function reverse(array) {
    return array.reverse();
 }

 function first(array) {
    return array[0];
 }

 const last = compose(first, reverse);
 console.log(last([1, 2, 3, 4]))